/**
 * @Author: Lenovo
 * @Date: 2024/7/11 17:55
 * @description:
 */
public class MySingleList implements IList {
    static class ListNode{
        public int val;
        public ListNode next;

        public ListNode(int val) {
            this.val = val;
        }
    }
    public ListNode head;
    public void create(){
        ListNode node = new ListNode(1);
        ListNode node2 = new ListNode(2);
        ListNode node3 = new ListNode(3);
        ListNode node4 = new ListNode(4);
        head = node;
        node.next = node2;
        node2.next = node3;
        node3.next = node4;
    }
    @Override
    public void addFirst(int data) {
        ListNode node = new ListNode(data);
        node.next = head;
        head = node;
    }

    @Override
    public void addLast(int data) {
        ListNode node = new ListNode(data);
        if(head == null){
            head = node;
            return;
        }
        ListNode cur = head;
        while (cur.next != null){
            cur = cur.next;
        }
        cur.next = node;
    }

    @Override
    public void addIndex(int index, int data) {
        int len = size();
        if (index < 0 || index > len){
            throw new CheckPos("位置不合法...");
        }
        if (index == 0){
            addFirst(data);
            return;
        }
        if (index == len){
            addLast(data);
            return ;
        }
        ListNode node = new ListNode(data);
        ListNode cur = head;

        while (index - 1 != 0){
            cur = cur.next;
            index-- ;
        }
        node.next = cur.next;
        cur.next = node;
    }
    @Override
    public boolean contains(int key) {
        ListNode cur = head;
        while (cur != null){
            if(cur.val == key){
                return true;
            }
            cur = cur.next;
        }
        return false;
    }

    @Override
    public void remove(int key) {
        if(head == null) {
            return;
        }
        if(head.val == key) {
            head = head.next;
            return;
        }
        ListNode cur = NodeOfKey(key);
        ListNode del = cur.next;
        cur.next = del.next;
    }
    private ListNode NodeOfKey(int key){
        ListNode cur = head;
        while (cur != null){
            if (cur.next.val == key){
                return cur;
            }
            cur = cur.next;
        }
        return null;
    }


    @Override
    public void removeAllKey(int key) {
        if(head == null){
            return;
        }
        ListNode prev = head;
        ListNode cur = head.next;
        while (cur != null){
            if (cur.val == key){
                prev.next = cur.next;
                cur = cur.next;
            }else{
                prev = cur;
                cur = cur.next;
            }
        }
        if (head.val == key){
            head = head.next;
        }
    }

    @Override
    public int size() {
        ListNode cur = head;
        int count = 0;
        while (cur != null){
            count++;
            cur = cur.next;
        }
        return count;
    }

    @Override
    public void clear() {
        ListNode cur = head;
        while(cur != null){
            ListNode curN = null;
            cur = null;
            cur = curN;
        }
        head = null;
    }

    @Override
    public void display() {
        ListNode cur = head;
        while (cur != null){
            System.out.print(cur.val+" ");
            cur = cur.next;
        }
        System.out.println();
    }
}